[sql] Import SQLite 3.17.0.

third_party/sqlite/src/src/vdbeapi.c

 /*
 ** 2004 May 26
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
@@ skipping 42 matching lines @@
   }
 }
 
 #ifndef SQLITE_OMIT_TRACE
 /*
 ** Invoke the profile callback.  This routine is only called if we already
 ** know that the profile callback is defined and needs to be invoked.
 */
 static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
   sqlite3_int64 iNow;
+  sqlite3_int64 iElapse;
   assert( p->startTime>0 );
-  assert( db->xProfile!=0 );
+  assert( db->xProfile!=0 || (db->mTrace & SQLITE_TRACE_PROFILE)!=0 );
   assert( db->init.busy==0 );
   assert( p->zSql!=0 );
   sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
-  db->xProfile(db->pProfileArg, p->zSql, (iNow - p->startTime)*1000000);
+  iElapse = (iNow - p->startTime)*1000000;
+  if( db->xProfile ){
+    db->xProfile(db->pProfileArg, p->zSql, iElapse);
+  }
+  if( db->mTrace & SQLITE_TRACE_PROFILE ){
+    db->xTrace(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
+  }
   p->startTime = 0;
 }
 /*
 ** The checkProfileCallback(DB,P) macro checks to see if a profile callback
 ** is needed, and it invokes the callback if it is needed.
 */
 # define checkProfileCallback(DB,P) \
    if( ((P)->startTime)>0 ){ invokeProfileCallback(DB,P); }
 #else
 # define checkProfileCallback(DB,P)  /*no-op*/
@@ skipping 76 matching lines @@
 }
 
 
 /**************************** sqlite3_value_  *******************************
 ** The following routines extract information from a Mem or sqlite3_value
 ** structure.
 */
 const void *sqlite3_value_blob(sqlite3_value *pVal){
   Mem *p = (Mem*)pVal;
   if( p->flags & (MEM_Blob|MEM_Str) ){
-    if( sqlite3VdbeMemExpandBlob(p)!=SQLITE_OK ){
+    if( ExpandBlob(p)!=SQLITE_OK ){
       assert( p->flags==MEM_Null && p->z==0 );
       return 0;
     }
     p->flags |= MEM_Blob;
     return p->n ? p->z : 0;
   }else{
     return sqlite3_value_text(pVal);
   }
 }
 int sqlite3_value_bytes(sqlite3_value *pVal){
   return sqlite3ValueBytes(pVal, SQLITE_UTF8);
 }
 int sqlite3_value_bytes16(sqlite3_value *pVal){
   return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
 }
 double sqlite3_value_double(sqlite3_value *pVal){
   return sqlite3VdbeRealValue((Mem*)pVal);
 }
 int sqlite3_value_int(sqlite3_value *pVal){
   return (int)sqlite3VdbeIntValue((Mem*)pVal);
 }
 sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
   return sqlite3VdbeIntValue((Mem*)pVal);
 }
 unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
-  return ((Mem*)pVal)->eSubtype;
+  Mem *pMem = (Mem*)pVal;
+  return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);
 }
 const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
 }
 #ifndef SQLITE_OMIT_UTF16
 const void *sqlite3_value_text16(sqlite3_value* pVal){
   return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
 }
 const void *sqlite3_value_text16be(sqlite3_value *pVal){
   return sqlite3ValueText(pVal, SQLITE_UTF16BE);
@@ skipping 160 matching lines @@
 }
 void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
 }
 void sqlite3_result_null(sqlite3_context *pCtx){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemSetNull(pCtx->pOut);
 }
 void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
-  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
-  pCtx->pOut->eSubtype = eSubtype & 0xff;
+  Mem *pOut = pCtx->pOut;
+  assert( sqlite3_mutex_held(pOut->db->mutex) );
+  pOut->eSubtype = eSubtype & 0xff;
+  pOut->flags |= MEM_Subtype;
 }
 void sqlite3_result_text(
   sqlite3_context *pCtx, 
   const char *z, 
   int n,
   void (*xDel)(void *)
 ){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
 }
@@ skipping 77 matching lines @@
   pCtx->isError = SQLITE_TOOBIG;
   pCtx->fErrorOrAux = 1;
   sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1, 
                        SQLITE_UTF8, SQLITE_STATIC);
 }
 
 /* An SQLITE_NOMEM error. */
 void sqlite3_result_error_nomem(sqlite3_context *pCtx){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemSetNull(pCtx->pOut);
-  pCtx->isError = SQLITE_NOMEM;
+  pCtx->isError = SQLITE_NOMEM_BKPT;
   pCtx->fErrorOrAux = 1;
-  pCtx->pOut->db->mallocFailed = 1;
+  sqlite3OomFault(pCtx->pOut->db);
 }
 
 /*
 ** This function is called after a transaction has been committed. It 
 ** invokes callbacks registered with sqlite3_wal_hook() as required.
 */
 static int doWalCallbacks(sqlite3 *db){
   int rc = SQLITE_OK;
 #ifndef SQLITE_OMIT_WAL
   int i;
   for(i=0; i<db->nDb; i++){
     Btree *pBt = db->aDb[i].pBt;
     if( pBt ){
       int nEntry;
       sqlite3BtreeEnter(pBt);
       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
       sqlite3BtreeLeave(pBt);
       if( db->xWalCallback && nEntry>0 && rc==SQLITE_OK ){
-        rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zName, nEntry);
+        rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
       }
     }
   }
 #endif
   return rc;
 }
 
 
 /*
 ** Execute the statement pStmt, either until a row of data is ready, the
@@ skipping 34 matching lines @@
     }
 #else
     sqlite3_reset((sqlite3_stmt*)p);
 #endif
   }
 
   /* Check that malloc() has not failed. If it has, return early. */
   db = p->db;
   if( db->mallocFailed ){
     p->rc = SQLITE_NOMEM;
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   if( p->pc<=0 && p->expired ){
     p->rc = SQLITE_SCHEMA;
     rc = SQLITE_ERROR;
     goto end_of_step;
   }
   if( p->pc<0 ){
     /* If there are no other statements currently running, then
     ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
     ** from interrupting a statement that has not yet started.
     */
     if( db->nVdbeActive==0 ){
       db->u1.isInterrupted = 0;
     }
 
     assert( db->nVdbeWrite>0 || db->autoCommit==0 
         || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
     );
 
 #ifndef SQLITE_OMIT_TRACE
-    if( db->xProfile && !db->init.busy && p->zSql ){
+    if( (db->xProfile || (db->mTrace & SQLITE_TRACE_PROFILE)!=0)
+        && !db->init.busy && p->zSql ){
       sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
     }else{
       assert( p->startTime==0 );
     }
 #endif
 
     db->nVdbeActive++;
     if( p->readOnly==0 ) db->nVdbeWrite++;
     if( p->bIsReader ) db->nVdbeRead++;
     p->pc = 0;
@@ skipping 20 matching lines @@
   if( rc==SQLITE_DONE ){
     assert( p->rc==SQLITE_OK );
     p->rc = doWalCallbacks(db);
     if( p->rc!=SQLITE_OK ){
       rc = SQLITE_ERROR;
     }
   }
 
   db->errCode = rc;
   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
-    p->rc = SQLITE_NOMEM;
+    p->rc = SQLITE_NOMEM_BKPT;
   }
 end_of_step:
   /* At this point local variable rc holds the value that should be 
   ** returned if this statement was compiled using the legacy 
   ** sqlite3_prepare() interface. According to the docs, this can only
   ** be one of the values in the first assert() below. Variable p->rc 
   ** contains the value that would be returned if sqlite3_finalize() 
   ** were called on statement p.
   */
   assert( rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR 
@@ skipping 46 matching lines @@
     ** finalized or reset the parser error message is available via
     ** sqlite3_errmsg() and sqlite3_errcode().
     */
     const char *zErr = (const char *)sqlite3_value_text(db->pErr); 
     sqlite3DbFree(db, v->zErrMsg);
     if( !db->mallocFailed ){
       v->zErrMsg = sqlite3DbStrDup(db, zErr);
       v->rc = rc2;
     } else {
       v->zErrMsg = 0;
-      v->rc = rc = SQLITE_NOMEM;
+      v->rc = rc = SQLITE_NOMEM_BKPT;
     }
   }
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }
 
 
 /*
 ** Extract the user data from a sqlite3_context structure and return a
@@ skipping 84 matching lines @@
   }
   return (void*)pMem->z;
 }
 
 /*
 ** Allocate or return the aggregate context for a user function.  A new
 ** context is allocated on the first call.  Subsequent calls return the
 ** same context that was returned on prior calls.
 */
 void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
-  assert( p && p->pFunc && p->pFunc->xStep );
+  assert( p && p->pFunc && p->pFunc->xFinalize );
   assert( sqlite3_mutex_held(p->pOut->db->mutex) );
   testcase( nByte<0 );
   if( (p->pMem->flags & MEM_Agg)==0 ){
     return createAggContext(p, nByte);
   }else{
     return (void*)p->pMem->z;
   }
 }
 
 /*
@@ skipping 70 matching lines @@
 /*
 ** Return the number of times the Step function of an aggregate has been 
 ** called.
 **
 ** This function is deprecated.  Do not use it for new code.  It is
 ** provide only to avoid breaking legacy code.  New aggregate function
 ** implementations should keep their own counts within their aggregate
 ** context.
 */
 int sqlite3_aggregate_count(sqlite3_context *p){
-  assert( p && p->pMem && p->pFunc && p->pFunc->xStep );
+  assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
   return p->pMem->n;
 }
 #endif
 
 /*
 ** Return the number of columns in the result set for the statement pStmt.
 */
 int sqlite3_column_count(sqlite3_stmt *pStmt){
   Vdbe *pVm = (Vdbe *)pStmt;
   return pVm ? pVm->nResColumn : 0;
@@ skipping 50 matching lines @@
 ** Check to see if column iCol of the given statement is valid.  If
 ** it is, return a pointer to the Mem for the value of that column.
 ** If iCol is not valid, return a pointer to a Mem which has a value
 ** of NULL.
 */
 static Mem *columnMem(sqlite3_stmt *pStmt, int i){
   Vdbe *pVm;
   Mem *pOut;
 
   pVm = (Vdbe *)pStmt;
-  if( pVm && pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
-    sqlite3_mutex_enter(pVm->db->mutex);
+  if( pVm==0 ) return (Mem*)columnNullValue();
+  assert( pVm->db );
+  sqlite3_mutex_enter(pVm->db->mutex);
+  if( pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
     pOut = &pVm->pResultSet[i];
   }else{
-    if( pVm && ALWAYS(pVm->db) ){
-      sqlite3_mutex_enter(pVm->db->mutex);
-      sqlite3Error(pVm->db, SQLITE_RANGE);
-    }
+    sqlite3Error(pVm->db, SQLITE_RANGE);
     pOut = (Mem*)columnNullValue();
   }
   return pOut;
 }
 
 /*
 ** This function is called after invoking an sqlite3_value_XXX function on a 
 ** column value (i.e. a value returned by evaluating an SQL expression in the
 ** select list of a SELECT statement) that may cause a malloc() failure. If 
 ** malloc() has failed, the threads mallocFailed flag is cleared and the result
@@ skipping 12 matching lines @@
 */
 static void columnMallocFailure(sqlite3_stmt *pStmt)
 {
   /* If malloc() failed during an encoding conversion within an
   ** sqlite3_column_XXX API, then set the return code of the statement to
   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
   ** and _finalize() will return NOMEM.
   */
   Vdbe *p = (Vdbe *)pStmt;
   if( p ){
+    assert( p->db!=0 );
+    assert( sqlite3_mutex_held(p->db->mutex) );
     p->rc = sqlite3ApiExit(p->db, p->rc);
     sqlite3_mutex_leave(p->db->mutex);
   }
 }
 
 /**************************** sqlite3_column_  *******************************
 ** The following routines are used to access elements of the current row
 ** in the result set.
 */
 const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
@@ skipping 97 matching lines @@
   n = sqlite3_column_count(pStmt);
   if( N<n && N>=0 ){
     N += useType*n;
     sqlite3_mutex_enter(db->mutex);
     assert( db->mallocFailed==0 );
     ret = xFunc(&p->aColName[N]);
      /* A malloc may have failed inside of the xFunc() call. If this
     ** is the case, clear the mallocFailed flag and return NULL.
     */
     if( db->mallocFailed ){
-      db->mallocFailed = 0;
+      sqlite3OomClear(db);
       ret = 0;
     }
     sqlite3_mutex_leave(db->mutex);
   }
   return ret;
 }
 
 /*
 ** Return the name of the Nth column of the result set returned by SQL
 ** statement pStmt.
@@ skipping 179 matching lines @@
 /*
 ** Bind a blob value to an SQL statement variable.
 */
 int sqlite3_bind_blob(
   sqlite3_stmt *pStmt, 
   int i, 
   const void *zData, 
   int nData, 
   void (*xDel)(void*)
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( nData<0 ) return SQLITE_MISUSE_BKPT;
+#endif
   return bindText(pStmt, i, zData, nData, xDel, 0);
 }
 int sqlite3_bind_blob64(
   sqlite3_stmt *pStmt, 
   int i, 
   const void *zData, 
   sqlite3_uint64 nData, 
   void (*xDel)(void*)
 ){
   assert( xDel!=SQLITE_DYNAMIC );
@@ skipping 137 matching lines @@
 }
 
 /*
 ** Return the name of a wildcard parameter.  Return NULL if the index
 ** is out of range or if the wildcard is unnamed.
 **
 ** The result is always UTF-8.
 */
 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
   Vdbe *p = (Vdbe*)pStmt;
-  if( p==0 || i<1 || i>p->nzVar ){
-    return 0;
-  }
-  return p->azVar[i-1];
+  if( p==0 ) return 0;
+  return sqlite3VListNumToName(p->pVList, i);
 }
 
 /*
 ** Given a wildcard parameter name, return the index of the variable
 ** with that name.  If there is no variable with the given name,
 ** return 0.
 */
 int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
-  int i;
-  if( p==0 ){
-    return 0;
-  }
-  if( zName ){
-    for(i=0; i<p->nzVar; i++){
-      const char *z = p->azVar[i];
-      if( z && strncmp(z,zName,nName)==0 && z[nName]==0 ){
-        return i+1;
-      }
-    }
-  }
-  return 0;
+  if( p==0 || zName==0 ) return 0;
+  return sqlite3VListNameToNum(p->pVList, zName, nName);
 }
 int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
 }
 
 /*
 ** Transfer all bindings from the first statement over to the second.
 */
 int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
   Vdbe *pFrom = (Vdbe*)pFromStmt;
@@ skipping 54 matching lines @@
 */
 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
 }
 
 /*
 ** Return true if the prepared statement is in need of being reset.
 */
 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
   Vdbe *v = (Vdbe*)pStmt;
-  return v!=0 && v->pc>=0 && v->magic==VDBE_MAGIC_RUN;
+  return v!=0 && v->magic==VDBE_MAGIC_RUN && v->pc>=0;
 }
 
 /*
 ** Return a pointer to the next prepared statement after pStmt associated
 ** with database connection pDb.  If pStmt is NULL, return the first
 ** prepared statement for the database connection.  Return NULL if there
 ** are no more.
 */
 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
   sqlite3_stmt *pNext;
@@ skipping 23 matching lines @@
   if( !pStmt ){
     (void)SQLITE_MISUSE_BKPT;
     return 0;
   }
 #endif
   v = pVdbe->aCounter[op];
   if( resetFlag ) pVdbe->aCounter[op] = 0;
   return (int)v;
 }
 
+/*
+** Return the SQL associated with a prepared statement
+*/
+const char *sqlite3_sql(sqlite3_stmt *pStmt){
+  Vdbe *p = (Vdbe *)pStmt;
+  return p ? p->zSql : 0;
+}
+
+/*
+** Return the SQL associated with a prepared statement with
+** bound parameters expanded.  Space to hold the returned string is
+** obtained from sqlite3_malloc().  The caller is responsible for
+** freeing the returned string by passing it to sqlite3_free().
+**
+** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
+** expanded bound parameters.
+*/
+char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
+#ifdef SQLITE_OMIT_TRACE
+  return 0;
+#else
+  char *z = 0;
+  const char *zSql = sqlite3_sql(pStmt);
+  if( zSql ){
+    Vdbe *p = (Vdbe *)pStmt;
+    sqlite3_mutex_enter(p->db->mutex);
+    z = sqlite3VdbeExpandSql(p, zSql);
+    sqlite3_mutex_leave(p->db->mutex);
+  }
+  return z;
+#endif
+}
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Allocate and populate an UnpackedRecord structure based on the serialized
+** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
+** if successful, or a NULL pointer if an OOM error is encountered.
+*/
+static UnpackedRecord *vdbeUnpackRecord(
+  KeyInfo *pKeyInfo, 
+  int nKey, 
+  const void *pKey
+){
+  UnpackedRecord *pRet;           /* Return value */
+
+  pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
+  if( pRet ){
+    memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nField+1));
+    sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
+  }
+  return pRet;
+}
+
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or deleted.
+*/
+int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  Mem *pMem;
+  int rc = SQLITE_OK;
+
+  /* Test that this call is being made from within an SQLITE_DELETE or
+  ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
+  if( !p || p->op==SQLITE_INSERT ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_old_out;
+  }
+  if( p->pPk ){
+    iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_old_out;
+  }
+
+  /* If the old.* record has not yet been loaded into memory, do so now. */
+  if( p->pUnpacked==0 ){
+    u32 nRec;
+    u8 *aRec;
+
+    nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
+    aRec = sqlite3DbMallocRaw(db, nRec);
+    if( !aRec ) goto preupdate_old_out;
+    rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);
+    if( rc==SQLITE_OK ){
+      p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
+      if( !p->pUnpacked ) rc = SQLITE_NOMEM;
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3DbFree(db, aRec);
+      goto preupdate_old_out;
+    }
+    p->aRecord = aRec;
+  }
+
+  pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
+  if( iIdx==p->pTab->iPKey ){
+    sqlite3VdbeMemSetInt64(pMem, p->iKey1);
+  }else if( iIdx>=p->pUnpacked->nField ){
+    *ppValue = (sqlite3_value *)columnNullValue();
+  }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
+    if( pMem->flags & MEM_Int ){
+      sqlite3VdbeMemRealify(pMem);
+    }
+  }
+
+ preupdate_old_out:
+  sqlite3Error(db, rc);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** the number of columns in the row being updated, deleted or inserted.
+*/
+int sqlite3_preupdate_count(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->keyinfo.nField : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is designed to be called from within a pre-update callback
+** only. It returns zero if the change that caused the callback was made
+** immediately by a user SQL statement. Or, if the change was made by a
+** trigger program, it returns the number of trigger programs currently
+** on the stack (1 for a top-level trigger, 2 for a trigger fired by a 
+** top-level trigger etc.).
+**
+** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
+** or SET DEFAULT action is considered a trigger.
+*/
+int sqlite3_preupdate_depth(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->v->nFrame : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or inserted.
+*/
+int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  int rc = SQLITE_OK;
+  Mem *pMem;
+
+  if( !p || p->op==SQLITE_DELETE ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_new_out;
+  }
+  if( p->pPk && p->op!=SQLITE_UPDATE ){
+    iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_new_out;
+  }
+
+  if( p->op==SQLITE_INSERT ){
+    /* For an INSERT, memory cell p->iNewReg contains the serialized record
+    ** that is being inserted. Deserialize it. */
+    UnpackedRecord *pUnpack = p->pNewUnpacked;
+    if( !pUnpack ){
+      Mem *pData = &p->v->aMem[p->iNewReg];
+      rc = ExpandBlob(pData);
+      if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
+      if( !pUnpack ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+      p->pNewUnpacked = pUnpack;
+    }
+    pMem = &pUnpack->aMem[iIdx];
+    if( iIdx==p->pTab->iPKey ){
+      sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+    }else if( iIdx>=pUnpack->nField ){
+      pMem = (sqlite3_value *)columnNullValue();
+    }
+  }else{
+    /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
+    ** value. Make a copy of the cell contents and return a pointer to it.
+    ** It is not safe to return a pointer to the memory cell itself as the
+    ** caller may modify the value text encoding.
+    */
+    assert( p->op==SQLITE_UPDATE );
+    if( !p->aNew ){
+      p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
+      if( !p->aNew ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+    }
+    assert( iIdx>=0 && iIdx<p->pCsr->nField );
+    pMem = &p->aNew[iIdx];
+    if( pMem->flags==0 ){
+      if( iIdx==p->pTab->iPKey ){
+        sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+      }else{
+        rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
+        if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      }
+    }
+  }
+  *ppValue = pMem;
+
+ preupdate_new_out:
+  sqlite3Error(db, rc);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 /*
 ** Return status data for a single loop within query pStmt.
 */
 int sqlite3_stmt_scanstatus(
   sqlite3_stmt *pStmt,            /* Prepared statement being queried */
   int idx,                        /* Index of loop to report on */
   int iScanStatusOp,              /* Which metric to return */
   void *pOut                      /* OUT: Write the answer here */
 ){
@@ skipping 48 matching lines @@
 }
 
 /*
 ** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
 */
 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
   Vdbe *p = (Vdbe*)pStmt;
   memset(p->anExec, 0, p->nOp * sizeof(i64));
 }
 #endif /* SQLITE_ENABLE_STMT_SCANSTATUS */